Install Apache Tomcat latest stable version on Ubuntu

Step1:
Update your apt-get package 

apt-get update

Step2:
Install Java Developer kit

sudo apt-get install default-jdk

Step3:
Install Java Developer kit

apt-get install tomcat8

Step3:
Install Java Developer kit

apt-get install tomcat8

step4:
Install Tomcat8 admin tools and documents

apt-get install tomcat8-docs tomcat8-examples tomcat8-admin

step5:
Run tomcat as service

systemctl start tomcat8

 To stop and restart service

systemctl stop tomcat8
systemctl restart tomcat8

NOTE: For security reasons, using the manager webapp is restricted to users with role "manager-gui". The host-manager webapp is restricted to users with role "admin-gui". Users are defined in /etc/tomcat8/tomcat-users.xml.
 Step6:

sudo vi /etc/tomcat8/tomcat-users.xml

<role rolename="manager-gui"/>
<role rolename="admin-gui"/>
<user username="admin" password="admin123" roles="manager-gui,admin-gui"/>